import math
x1, y1, x2, y2 = map(float,input().split())
a = math.sqrt(abs(x1-x2)**2+abs(y1-y2)**2)
print(f'{a:.8f}') import math math x1, y1, x2, y2 = map(float,input().split()) x1 map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 a = math.sqrt(abs(x1-x2)**2+abs(y1-y2)**2) a math.sqrt(abs(x1-x2)**2+abs(y1-y2)**2) math.sqrt math sqrt abs(x1-x2)**2+abs(y1-y2)**2 abs(x1-x2)**2 abs(x1-x2) abs x1-x2 x1 x2 2 abs(y1-y2)**2 abs(y1-y2) abs y1-y2 y1 y2 2 print(f'{a:.8f}') print f'{a:.8f}' x1, y1, x2, y2 = map(float,input().split()) map(float,input().split()) x1 y1, x2, y2 = map(float,input().split()) map(float,input().split()) y1 y2 = map(float,input().split()) map(float,input().split()) y2 a = math.sqrt(abs(x1-x2)**2+abs(y1-y2)**2) math.sqrt(abs(x1-x2)**2+abs(y1-y2)**2) a x2, y2 = map(float,input().split()) map(float,input().split()) x2
import math
x1, y1, x2, y2 = map(float,input().split())
a = math.sqrt(abs(x1-x2)**2+abs(y1-y2)**2)
print(f'{a:.8f}')
